Yes I try to use Flat rate shipping through USPS on everything that I sell it is often cheaper then doing it by weight you just need to make sure the item fits in a Flat rate box though. They come in small, medium, and large flat rate boxes. Flat rate is only $6.25 for a small flat rate box, $12.50 for a medium flat rate box and I think $18 for a large flat rate box but you get a discount on Ebay if you pay for postage on Paypal. Unless the item doesn't fit into a flat rate box then you have no choice but to do it by weight in which case just make sure you weigh it correctly and enter the correct dimensions on Paypal. People usually don't mind paying for shipping on most items is what I have found so just charge for shipping unless it is a really small item.